Bitcoin Researchers Tackle Quantum Threat with Multiple Approaches

The threat of quantum computers cracking Bitcoin wallets has been a topic of discussion for some time. A sufficiently powerful quantum computer could, in theory, derive private keys from exposed public keys using Shor's algorithm, making it possible to forge signatures and drain the wallet. The hypothetical arrival of such a machine is referred to as 'Q-Day.'

Researchers are working on fixes to address this problem, which fall into three buckets: quantum-safe transactions under current rules, protocol upgrades like a soft fork, and custody-layer defenses. This week saw news on each of these areas.

One approach is making quantum-resistant transactions work under Bitcoin's current rules. StarkWare, which mined the first quantum-safe Bitcoin transaction on mainnet last month, reported that an open competition reduced the estimated cost of building such a transaction from around $320 to roughly $67 in just one week. However, this is only a workaround and does not provide long-term protection.

Another approach involves protocol upgrades, which would change Bitcoin itself to adopt post-quantum signatures. This is considered the durable fix but requires years of design, testing, and deployment, and the community has only recently begun engaging with it.